If you wanted to do a complete PF-only conversion then yes, that would likely be the most appropriate conversion; 6 Rog/3 Ftr might also work.
Alternatively, you could just leave him as-is, convert his Grapple to CMD and rearrange his skills to suit Pathfinder (Stealth instead of Hide/MS, etc.) and be just fine.
I'd suggest the rogue/fighter combo that Orthos mentioned, if you don't want to just convert the class over. I did the latter, keeping the dread pirate abilities and switching the skills and feat amounts to PF.